not more. If he fasts a month from the start of the crescent moon and becomes sick during it for known days, or if a woman menstruates during it then becomes pure before its conclusion, he makes up the days he broke the fast according to their count if the month was complete. If it was incomplete, is he obligated to bring an additional day? There are two views regarding this, based on what we mentioned regarding breaking the fast on the day of 'Eid and the days of Tashriq.

Section: Whoever vows to fast a month is given a choice between fasting a month by the crescent moon—which is to start it from its beginning, in which case it suffices him—and fasting it by count, thirty days. Is he obligated to observe succession? There are two views. One is that he is obligated to; this is the view of Abu Thawr, because the unrestricted term "month" implies succession. The second is that he is not obligated to observe succession; this is the view of Al-Shafi'i and Muhammad ibn al-Hasan, because the word "month" refers to the period between two crescents or thirty days, and there is no disagreement that thirty days suffices him, so succession is not incumbent upon him, just as if he had vowed thirty days. As for if he vows to fast thirty days, he is not obligated to observe succession in them; Ahmad explicitly stated this. It has been narrated from Ahmad, regarding one who said: "I have vowed to Allah to fast ten days," that he should fast them successively. This indicates the obligation of (6) succession in vowed days. Some of our companions interpreted Ahmad's statement as applying to one who stipulated succession or intended it, because the term "ten" does not imply succession, and a vow does not necessitate it unless it is in his wording or intention. Others said: Ahmad's statement is to be taken literally, and succession is obligatory in the vow of ten, but not for thirty, because thirty is a month; if (7) he had intended succession, he would have said "a month." Thus, his shift to the count is evidence of the intent for separation, unlike the case of ten. The correct view is that he is obligated to observe succession, for the absence of evidence for separation is not evidence for the intent of succession; Allah the Almighty said regarding the makeup of Ramadan: "[He should complete] the period (i.e., of days) [by fasting] on other days" (8), and He did not mention their separation or their succession, and yet succession is not obligatory for them by consensus. Some of our companions said: If he vows to perform i'tikaf (seclusion) for a number of days, he is obligated to observe succession, and he is not obligated to the same in fasting, because i'tikaf connects parts to one another without separation, whereas fasting is interrupted by the night, which separates parts from one another; for this reason, if he vows to perform i'tikaf for two successive days, the night enters into it. The correct view is to treat them as equal, because what is obligatory is what his words imply, and his words do not imply succession, as evidenced by the vow of fasting, and what they mentioned regarding custom has no bearing. Whoever says: He is obligated to...